Crimping device



g- 1939. R. R. NYDEGGER 2,171,371

' CRIMPING DEVICE Filed Dec. 24, 1957 3 Sheets-Sheet 1 f V 7L9.

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ATTORNEY-1 29, 1939- R. RNYDEGGER 2,171,371

CRIMPING DEVICE Filed Dec. 24/1937 3 Sheets-Sheet 2 RoZano 1?. 053958? INVENTOR.

- ATTORNEY g- 29, 1939- R. R. NYDEGGER 2,171,371

CRIMPING DEVICE Filed 0'90. 24, 19s? 3 Sheets-Sheet 3 Rah/ d R. )Yydey'yer INVEN T0R.I

A TTORNEY Patented Aug. 29, I939 DEVICE Roland RoswellNydegger, Wilmington, DeL', assignor to E. I. du Pont de Nemours & Company, Wilmington, Del, a corporation of Delaware Application December 24,1937, Serial No. 181,646

4' Claims. (o1. se -22) The present invention relates to a new and improved crimping device, and, in particular, to

a device suitable for crimping blasting cap shells.. The art of crimping shells had its origin in the manual operation performed with modified pliers, or the like, in securing-fuse in ordinary blasting initiators. Such means failed to produce a uniform bead around the shell and the crimp formed did not effect a waterproof joint between said fuse and shell.

Withthe devising of a satisfactory resilient plug for electric blasting initiators, as disclosed and claimed in the co-pending case Serial No. 181,645, filed Dec. 24, 1937, it becomes even more necessary to have a crimping device free from r the foregoing disadvantages.

tially central enlargement, preferably circular in form, to permit free insertion or withdrawal of the shell. The remainder of the slot, on each 'side of the central enlargement, has a width smaller than the outer diameter of the shell,

to cause the formation of a uniform concave or internal bead on the shell, when the crimping blade is reciprocated. The end portions of the slot are substantially semi-circular in form and play an important role in effecting an absolutely uniform bead around the shell. The side and end portions of the slot are bounded 'bya ,crlmping edge of predetermined width and sharpness dependent on the depth and slope" of crimp.

The crimping blade may be reciprocated by hand or any suitable actuating means. I prefer to employ cranking means for this purpose.

The shell is preferably held rigid during the reciprocation of the'blade. Although any suitable anchoring device may be employed for this purpose, I prefer to use blocks which, when draw together, form a groove for retention of the shell. Desirably these blocks are so actuated by cam action, or the like, that they separate and release the shell after it has returned to a central position with respect to the crimping blade. The camming lever may 'be actuated bythe same crank which actuates'the' crimping blade.

The invention may be more readily understood .by reference to the drawings which represent merely a. preferredembodiment and are not intended to act as a limitation upon the scope of ingblade resting in one anchoring block. Figure 4 is a view of the blade between both blocks. Figure 5 isa view of a crimped shell. Figure 6 represents mechanical means for actuating the device and reciprocating the crimping blade. Figure 7 isa view of. a plurality of crimping blades between. both blocks. Figure 8 is a view of a shell provided with asplurality of crimps.

Referring in greater detail to the drawings, the crimping blade I of Figure l is provided-with the slot, 2 of preferred shape, as indicated by the substantially central enlargement 3 for introduction of the shell, narrow side portions i and 5, and semi-circular end portions 6 and 1.. The

section la|a of the blade illustrates the crimping edge 8,. which desirably bounds the side and end portions of the slot. -In assembling the I crimping device, the crimping blade I is placed in the groove 9 of Figure 2. between the anchoring blocks l and II, as shown in Figures 3 and 4,

, and the enlargement 3 is aligned with the aperof the crank in Figure 6, the central enlargement of the slot is shifted, and one end portion comes in contact withthe walls of the shell. This action imparts a uniform concave or internal bead half way around the circumferenceof said shell. As the stroke continues,,*-the other end portion is brought into similar contact with'the shell, thus effecting a bead around the remaining portion of the circumference, completing the, crimp. The central enlargement of the slot then returns to its starting position to permit the removal of the crimped shell, the blocks being separatedat this time. The completed crimp l3 isshown in Figure 5.

Figure 6shows one method of actuating-the crimping blade I and for maintaining the blocks in place during-the crimping operation. Figure 6 is a plan view of the crimping blocks and crank shaft l8 which is held to base plate 22 by bearings 2i. l4 illustrates a crank shaft head which may be driven by means of a belt attachment or other well-known drive mechanism. The crimp.- ing blade I is connected to said crank shaft by means of the connecting rod It, being fastened thereto at H, while the other end of. the connecting rod surrounds the crank pin at I5. The distance which the crimping blade'reciprocates is, of course, determined by the design of said crank pin, which design is in. turn governed by the length of crimping slot in the crimping blade.

The crimping blocks I0 and II are also held to base plate 22, block l0 being held securely with screws 20 .while block II is held slideably by cleats l9. Spring 23 acts continuously on block II to open aperture I2. Opposing the action of spring 23 is contact screw 28 which is actuated by lever 24 to pivot at 29 by the action of cam mounted on crank shaft 18. Cam 25 has one groove into which roller 21 may descend so that blocks l0 and H may separate under the action of spring 23 during the loading operation. The mechanism, as shown, is holding a shell and crimping the side away from the crank shaft II! which is rotating in a clock-wise direction. This represents the first quarter of the crimping cycle.

In the foregoing detailed description, the principle of the device according to my invention has been described with reference to a single crimping blade. 'In actual operation I prefer to employ a plurality of said crimping blades. This preferred embodiment is illustrated in Figure 7 which shows two such crimping blades, l and l-b placed in grooves one over the other between the anchoring blocks l0 and II. The enlargement 3 in the slot of each of these blades is aligned with the aperture l2 formed by joining the blocks l0 and II, so that the shell can be inserted readily. In the crimping operation, we prefer to reciprocate both blades at the same time about a shell-contained in aperture l2, said reciprocating action being carried out as described in the foregoing-in connection with 'the single blade. As a result of operating with two blades, the completed crimp will take the form shown as i3 and l3-a of Figure 8. Naturally, I do not intend to be limited to two blades, but may employ any number of said crimping blades.

Several outstanding advantages are attained with the use of my crimping device. When this device is employed to crimp a-shell about theresilient plug disclosed and claimed in my co-pending application, Serial No. 181,645, filed Dec. 24. 1937, for example, an absolutely "waterproof closure is attained. 1

In addition, the bead thus formed is absolutely uniform, and the crimping mechanism is extremely simple, having a relatively small number of moving parts. The latter factor lends greater safety in operation, wherever'explosives are involved. The simple reciprocating stroke of my device is a distinct advance over the devices of the art wherein either the shell or the crimping means must be reversed or the use of moving jaws be employed to complete the crimp.

In the foregoing description, the'crimping device has been designed in general for producing a single crimp in the cap shell. derstood, however, that two or more crimps may be produced in the same shell, either simultane- It should be 'un-' in co-pending case Serial No. 181,645, filed Dec. 24, 1937, the crimping device is not limited to such use but is of advantage in any situation where a uniform bead about a cylindrical shell is desired, and especially for crimping fuses in place in ordinary blasting initiators.

As many widely different embodiments may be employed without departing from the spirit and scope of my invention, I intend to be limited only by the following claims.

I claim:

1. A device for crimping shells, comprising a' blade provided with a. crimping slot of predeterv mined width bounded-by crimping edges substantially parallel but converging at each end of said slot to form substantially semicircular end portions, said crimping slot.being provided witl: a'

' blade provided with a crimping slot of predeter-- mined width bounded by crimping edges substantially parallel but converging at each end of said slot to form substantially semicircular end portions, said crimping slot being provided with a substantially central enlargement adapted to receive a shell substantially at right angles to the plane (K- said blade, anchoring means for retaining said shell in fixed position including a grooved block, said crimping blade being disposed substantially at right angles to the longitudinal axis of said groove, and means for reciprocating said blade to form a uniform head around said shell.

, 3. A device for crimping shells, comprising a blade provided with a crimping slot of predetermined width bounded by crimping edges substantially parallel but convergingat each end of said slot to form substantially semicircular end por tions, said crimping slot being provided with a substantially central enlargement adapted to receive a shell substantially at right angles to theplane of said blade, anchoring means including a block having one groove adapted to retainsaid shell in fixed position and a second groove substantially at right angles to and intersecting said first groove, said crimping blade being movably disposed in said second groove so that the central enlargement in the crimping slot is adapted to-center with said first groove to receive said I jshell, and means for reciprocating said blade in said second groove to around said shell.

4. A device for crimping shells,'comprising a plurality of crimping blades each provided with a crimping slot of predetermined width bounded by crimping edges substantially parallel but converging at each end of said slot to form substantially semicircular end portions, said crimping slot being provided with a substantially central enlargement adapted to receive ashell substantially at right angles to the plane of said blade,

anchoring means for retaining said shell in fixed position including a grooved block, said crimping blades being disposed substantially at right angles to the longitudinal axis of said groove, and means for reciprocating 'said blades to form uniform beads around said shell.

. ROLAND R. NYDEGGER.

form a uniform crimp- 

